Umbilical hernia prosthesis

ABSTRACT

The present invention relates to a prosthesis (200) comprising: one mesh (1) delimited by a peripheral exterior edge (1a), a frame (2) fastened to said mesh and adopting the shape of said peripheral exterior edge of the mesh, said frame being set back from said peripheral exterior edge and being provided with two hinge points (3a, 3b), the line passing through said two hinge points also passing through the centre (1b) of the mesh and thus forming a line M for folding the mesh in two, characterized in that said prosthesis further comprises at least two anchor pieces (5) made of suturable material and located on a single face of the mesh (1) on either side of said folding line, each piece having a fixed part (5a) linked to said mesh and a free part (5b), said free part being linked to at least one thread-shaped element (7).

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.14/232,378 filed Mar. 24, 2014, which is a National Stage Application ofPCT/EP2012/062672 filed Jun. 29, 2012, which claims benefit of andpriority to French Patent Application Serial No. 11/56425 filed Jul. 13,2011, and the disclosures of each of the above-identified applicationsare hereby incorporated by reference in their entirety.

The present invention provides a prosthesis, for repairing hernias, forexample, comprising a mesh and a member for reinforcing the mesh.

In humans the abdominal wall consists of fat and muscles interconnectedby aponeuroses. A break in continuity may occur at the level of theaponeuroses, allowing part of the peritoneum to pass through and form asac, known as a hernia, containing either fat or a portion of theintestine. Hernias or ventral ruptures (hernias occurring on a parietalsurgical scar) are manifested by a protrusion on the surface of the skinand are called umbilical or inguinal hernias or ventral ruptures, forexample, as a function of their location.

To repair a hernia, surgeons often fit a synthetic mesh prosthesis thatreplaces or reinforces the weakened anatomical tissue.

However, the efficacy of the prosthesis, and thus minimizing the risk ofrelapse, depend to a great degree on the proper fixing of theprosthesis. In particular, before being fixed, the prosthesis must becorrectly spread over the abdominal wall that it is intended toreinforce. Prostheses of mesh type, i.e. based on an arrangement ofthreads forming a textile, are generally flexible, and to introduce theminto the hernia they are often folded to reduce their volume. Theytherefore tend to form creases on the abdominal wall when they areintroduced onto the implantation site. In this respect spreading themout is of primary importance but may prove difficult, in particular inthe case of treating an umbilical hernia, which, being smaller than aninguinal hernia, offers little working space and little visibility formanipulation of the prosthesis by the surgeon.

In the case of umbilical hernias, for example, or when the aim oftreatment is to repair trocart holes or preventive, the size of thedefect to be treated is small, for example from 1 to 4 cm diameter, andopen surgery may be envisaged without widening the defect. However, inthis type of surgery, the surgeon has little working space and littlevisibility. It would thus be preferable to have a prosthesis that iseasy to position, to spread out and to fix, if possible avoiding thenecessity for sutures at the periphery of the prosthesis, which iscomplicated and laborious under such working conditions.

Failure to spread the prosthesis out perfectly against the abdominalwall leads to the risk of trapping the peritoneal sac and the risk ofinsertion of a soft organ between the prosthesis and the abdominal wall,which can lead to the risk of adhesions, pain and intestinal blockageand increase the possibility of relapse. It is therefore essential forthe surgeon to be sure that no part of the prosthesis remains folded andthat no viscera or any part of the intestines lie between the prosthesisand the abdominal wall. Moreover, incorrect positioning of the suturesor incorrect fixing of the prosthesis risks distortion of the prosthesisand the creation of tensions.

Thus in the case of an umbilical hernia in particular, having a smallorifice for introducing the prosthesis, it would be beneficial to have aprosthesis adapted to occupy a small volume in a first configuration inorder to facilitate its introduction into the abdominal cavity via saidorifice and then to be deployed, spread out and pressed easily againstthe abdominal wall so that the surgeon is sure of the optimalpositioning of the prosthesis and can moreover fix the prosthesisefficaciously without sutures at its periphery, and this, despite thelittle intrinsic visibility of small size hernias.

Various prostheses that may be folded up and then deployed areavailable.

The present invention concerns a prosthesis that is adapted to be foldedup in order to reduce the volume that it occupies at the time of itsintroduction into a small incision and on the other hand to be spreadout and fixed easily so that the surgeon is sure of the perfectspreading of the prosthesis and that it may be fixed efficaciously at acertain distance between the centre of the prosthesis and its peripherywithout sutures at the periphery of the prosthesis and this, despite thelittle intrinsic visibility of small size hernias.

The prosthesis of the invention is beneficial for treating hernias ofthe abdominal wall, in particular for treating umbilical hernias wherethe defect is small.

A first aspect of the present invention provides a prosthesiscomprising:

at least one flexible mesh delimited by a peripheral exterior edge,

at least one member for reinforcing said mesh, said reinforcing membertaking the form of a frame fastened to said mesh and substantiallyadopting the shape of said peripheral exterior edge of the mesh, saidframe being set back from said peripheral exterior edge and beingprovided with two hinge points, the line passing through said two hingepoints also passing through the centre of the mesh and thus forming aline M for folding the mesh in two,

characterized in that said prosthesis further comprises at least twoanchor pieces made of suturable material and located on a single face ofthe mesh on either side of said folding line, each piece having a fixedpart linked to said mesh and a free part, said free part being linked toat least one thread-shaped element.

The reinforcing member or frame may be rigid or have some flexibility.According to the present invention, the mesh and thus the prosthesis canbe folded in two because of the presence of the two hinge points of theframe, regardless of the presence or not of intrinsic elastic propertiesof the frame.

In the context of the present application the term “mesh” refers to anarrangement of biocompatible threads, for example a knitted, woven ornon-woven material, preferably of the openwork kind, i.e. having poresencouraging tissue recolonization. Such a mesh may be bioresorbable,partly bioresorbable or permanent. It is sufficiently flexible to befolded up at the time of its introduction into the abdominal cavity. Themesh may be produced from one layer of textile or from a plurality oflayers of textiles. Such meshes are well known to the person skilled inthe art. The mesh usable for the invention may be supplied in any shape(rectangular, square, circular, oval, etc.) and then cut to match theshape of the hernia defect. For example, the mesh may have the overallshape of a disc or an oval: in this case the frame also has a circularor oval shape and is preferably in the form of a ring. Alternatively,the mesh may have a globally square or rectangular shape: in this casethe frame also has a square or rectangular shape. The frame is set backfrom the exterior peripheral edge of the mesh: thus, whilst adopting theshape of the contour of the mesh, the frame has an exterior perimetersmaller than that of the exterior peripheral edge of the mesh: in otherwords, the exterior peripheral edge of the mesh extends a certaindistance beyond the frame. This distance may be greater than or equal to1 mm, for example. In other words also, the frame and the exteriorperipheral edge of the mesh are of similar geometric shape but the frameshows dimensions which are less than that of the exterior peripheraledge of the mesh.

As will become apparent from the following description, the shape of theframe and its location, set back slightly from the exterior peripheraledge of the mesh, enable the surgeon, when implanting the prosthesis, tofix it to the peritoneum efficaciously without requiring sutures at theperiphery of the mesh: the surgeon is able to fix the prosthesis alongthe interior contour of the frame only, said interior contour defining astitches fixing line: this avoids the surgeon having to apply stitchesto the prosthesis at the exterior peripheral edge of the mesh, which isdifficult to reach and hardly visible because of the small size of theincision. The interior contour of the frame of the prosthesis of theinvention defines a fixing line, or stitching line, locatedapproximately half way between the centre of the mesh and its exteriorperipheral edge, along which the surgeon may locate the stitches when hefixes the prosthesis to the abdominal wall. Nevertheless, perfectspreading out of the prosthesis is assured by the presence of the framewhich, by adopting the shape of the contour of the exterior peripheraledge, ensures deployment of the prosthesis and pressing thereof onto theabdominal wall.

In the context of the present application, by “anchor piece made ofsuturable material” is meant that the anchor piece is capable of beinglinked to, or passed through by, a thread-shaped element as defined inthe present application, without being torn off when a user, such as asurgeon for example, exerts a moderate tension on said thread-shapedelement, such as the necessary tension for orientating and/orpositioning the prosthesis in the implantation site, as describedhereinafter. Thus the anchor piece may be under the form of a textile,either knitted, woven or nonwoven, open worked or not; alternatively orin addition, the anchor piece may be under the form of a film or a sheetof material, as long as this textile, film and/or sheet of material isnot torn off under the effect of the moderate tension as described aboveexerted on a thread-shaped element linked to, or passing through, saidtextile, film and/or sheet.

The anchor pieces may be made of bioresorbable material or not. Thebioresorbable material may be chosen, for example, from polylactic acid(PLA), polycaprolactone (PCL), polydioxanone (PDO), trimethylenecarbonate (TMC), polyvinyl alcohol (PVA), polyhydroxyalkanoate (PHA),oxidized cellulose, polyglycol acid (PGA), copolymers of these materialsand mixtures thereof.

As will be apparent from the following description, the anchor piecesare useful to the surgeon for facilitating the positioning of theprosthesis in the centre of the defect to be treated, and for attachingthe prosthesis to the biological tissues. The anchor pieces also formthe parts of the prosthesis by which said prosthesis is sutured to theabdominal wall.

The anchor pieces of the prosthesis of the invention are located on onesingle face of the mesh: as will be apparent from the followingdescription, the anchor pieces are located on the face of the meshintended to face the abdominal wall once the prosthesis is implanted:indeed, said anchor pieces are intended to be reached by the surgeonthrough the incision made for the implantation, in particular by meansof thread-shaped elements, in view of assisting the surgeon to orientateand position the prosthesis as well as to raise the edges of the herniadefect for visualising the area to be stitched, when the prosthesis isput in place. The prosthesis of the invention thus comprises at leasttwo anchor pieces located on either side of the folding line, preferablyat two places which are symmetrical to each other with respect to thisfolding line: such a location of the anchor pieces enables the surgeonto expand the prosthesis optimally when it is put in place. According tothe invention, the number of anchor pieces is not limited and theprosthesis may comprise 3 or 4 anchor pieces, even more. Each anchorpiece shows a fixed part linked to the mesh of the prosthesis, and afree part, not attached to the mesh, and forming a type of shutter, flapor flying part. The fixed part of the anchor piece may be linked to themesh by gluing, welding, sewing or by any biocompatible fixing means. Inone embodiment, the anchor pieces are linked to the mesh via their fixedpart by means of the reinforcing member.

The anchor pieces may show any geometrical shape. They may be identicalor different.

In one embodiment, each anchor piece having a geometrical shape with atleast one side having a length equal or greater than that of the othersides, each anchor piece is linked to the mesh by its longest side,along a direction perpendicular to the segment linking the centre of themesh and the point of fixation of said piece in the plane of the mesh.In such an embodiment, each anchor piece being linked to the mesh by itslongest side, the free part, or shutter or flap of each piece occupiesonly little space in the surroundings of the mesh: this enablesmaintaining a clear and non obstructed space around the hernia defectwhen the prosthesis is put in place and therefore allows the surgeonhaving a good visibility of the implantation site and not being impededby the presence of useless extra elements. Such an embodiment alsoenables a more secure fixation of the anchor pieces to the mesh.Moreover, the positioning of the anchor pieces, i.e. along a directionperpendicular to the segment linking the centre of the mesh and thepoint of fixation of said piece in the plane of the mesh, allows thesurgeon to position the prosthesis optimally by pulling on thethread-shaped elements linked to the anchor pieces in a centrifugaldirection with respect to the hernia defect, as will be apparent in thefollowing description.

In one embodiment, the suturable material is a textile and the anchorpieces are textile pieces. This textile may be identical to that of themesh, or different. For example, the anchor pieces may be sewn to themesh.

In the context of the present application, by “thread-shaped element”,is meant a flexible and elongated element, the length of which is muchmore greater than its thickness and its width, the contour of the crosssection of which is globally circular: examples of thread-shapedelements of the invention may be a thread on its own, composite or not,or several threads, for example arranged together to make a braid, atube, and combinations thereof. In embodiments, the thread-shapedelements are selected from threads, flexible tubes and combinationsthereof.

In the prosthesis of the invention, the free part of each anchor pieceis linked to at least one thread-shaped element. As will be apparentfrom the detailed description below, the thread-shaped element isintended to allow the surgeon to pull on the anchor piece linked theretoin order to expand, orientate and position the prosthesis when saidprosthesis is put in place: preferably, the surgeon will pullsimultaneously on the thread-shaped elements of the at least two anchorpieces which are present in order to counterbalance the prosthesis withrespect to the defect to be treated. In addition, due to its structure,the thread-shaped element does not unnecessarily encumber the workingarea for the surgeon, said area being already naturally particularlylimited regarding small size hernias.

In embodiments, the thread-shaped elements are flexible tubes: becauseof their hollow structure, necessitating a certain outer diameter, forexample equal or greater than 3 mm, the tubes show a quite importantouter surface capable of being in contact with the margins of thedefect, this allowing decreasing dramatically the potential traumaticeffect due to the contact of the tubes with the margins of the defect.The flexibility of the tubes allows their easy handling with no risk ofdamaging the tissues. Preferably, the tubes are flexible and semi-rigid.As will appear from the following description, such a semi-rigidity ofthe tubes allows maintaining the anchor pieces to which they are linkedunder slight tension, without having to apply any particular tension onthese tubes. The flexible tubes may be in plastic material, silicone, ora combination of these materials.

In one embodiment of the invention, the mesh of the prosthesis of theinvention is a knitted fabric: because of the stitches that form it, aknitted fabric makes it possible to obtain openwork faces encouragingcellular recolonization after implantation. The knitted fabric may be atwo-dimensional knitted fabric or a three-dimensional knitted fabric.

In the context of the present application, the expression“two-dimensional knitted fabric” means a knitted fabric having twoopposite faces linked together by stitches but having no spacersimparting a certain thickness to it: such a knitted fabric may beobtained, for example, by knitting threads on a warp or Raschel knittingmachine using two guide bars. Examples of two-dimensional knittedfabrics suitable for the present invention are given in the documentWO2009/071998.

In the present application, the expression “three-dimensional knittedfabric” means a knitted fabric having two opposite faces linked togetherby spacers imparting a significant thickness to the knitted fabric, saidspacers consisting of connecting threads additional to the threadsforming the two faces of the knitted fabric. Such a knitted fabric maybe obtained, for example, using a double-bed Raschel knitting machine orwarp knitting machine with a plurality of guide bars. Examples ofknitting three-dimensional knitted fabrics suitable for the presentinvention are given in the documents WO99/05990, WO2009/031035,WO2009/071998.

In one embodiment, said frame is set back from the exterior peripheraledge of the mesh and is of serpentine shape, forming undulations. Forexample, said frame is in the form of a flat ribbon forming undulationssubstantially in the plane of said mesh. As will become apparent fromthe description given hereinafter, this configuration of the frame makesit possible, when fixing the prosthesis to the biological tissue, toexecute a suture in the prosthesis at a given location without deformingthe prosthesis as a whole during this operation; deformation of theprosthesis caused by the suture at the given location is smoothed out bythe undulating frame. Thus the frame and therefore the rest of theprosthesis remain correctly positioned, and in particular remain pressedagainst the abdominal wall, during the fixing of the prosthesis.

In one embodiment, said reinforcing member is produced in bioresorbablematerial. Thus the reinforcing member fulfils its role of stiffening theprosthesis during positioning and implantation of the prosthesis and isthen degraded progressively once the mesh is recolonized by thesurrounding cells.

The bioresorbable material may be chosen, for example, from polylacticacid (PLA), polycaprolactone (PCL), polydioxanone (PDO), trimethylenecarbonate (TMC), polyvinyl alcohol (PVA), polyhydroxyalkanoate (PHA),oxidized cellulose, polyglycol acid (PGA), copolymers of these materialsand mixtures thereof.

Alternatively, the reinforcing member is produced in a non-bioresorbablematerial chosen from polypropylene, a polyester such as polyethyleneterephthalate, polyamide, silicone, polyetheretherketone (PEEK),polyaryletheretherketone (PAEK) and mixtures thereof.

In another embodiment, said reinforcing member is produced from acombination of bioresorbable material and non-bioresorbable material.

In one embodiment of the invention said mesh has the shape of a disc,said frame being substantially in the form of a circular ring. In suchan embodiment, said anchor pieces may be fixed to two diametricallyopposed places of an inner perimeter of said ring, said two places beingspaced by 90° from each of said two hinge points. Such an embodimentenables an optimal deployment of the prosthesis by pulling in oppositedirections on the respective thread-shaped elements of the two anchorpieces after the folded prosthesis has been introduced in theimplantation site.

Alternatively, the prosthesis comprises four said anchor piecesdistributed substantially regularly along an inner perimeter of saidring so that two anchor pieces are located on one side of the foldingline and the other two anchor pieces are located on the other side ofsaid folding line. In such an embodiment, for example, a singlethread-shaped element links together the free parts of two anchor pieceslocated on the same side of the folding line. The total number ofthread-shaped elements thus remains low and the surgeon is not impededby the presence of extra thread-shaped elements. Moreover, thedeployment and orientation step of the prosthesis is rendered easier:indeed, each thread-shaped element, because it links together the freeparts of two anchor pieces located on the same side of the folding line,forms a sort of loop that the surgeon may very easily grasp and handle,in particular in view of exerting a tension on this loop: in addition,such a tension enables pulling on two anchor pieces simultaneously, attwo different places of the mesh, thereby allowing optimised deploymentand spreading out of the mesh and of the prosthesis.

Alternatively, a single thread-shaped element may link together the freeparts of two adjacent anchor pieces located on each side of the foldingline.

In embodiments, the anchor pieces have a colour different than that ofthe mesh. Alternatively or in addition, the thread-shaped elements havea colour different than that of the mesh and than that of the anchorpieces. Thanks to the present invention, the surgeon works in a relativenon obstructed implantation site where he can see the area of theprosthesis to be attached to the abdominal wall, this area being locatedmore or less in the middle between the centre of the mesh and the edgeof the mesh: such embodiments of the prosthesis of the invention allowthe surgeon to easily and rapidly make the necessary stitches byenabling him, thanks to the different colours, to quickly identifywhether he handles the mesh, the anchor pieces or the thread-shapedelements.

In one embodiment of the invention, the face of the mesh opposite thatincluding said anchor pieces is covered with a non-adherent coating.

Such a coating makes it possible in particular to avoid the formation ofunwanted severe post-operative fibrous adhesions.

In the context of the present application the expression “non-adherent”refers to a non-porous, smooth, biocompatible coating or materialoffering no space for cellular recolonization and preferably encouragingthe birth of a peritoneum.

In embodiments, where the prosthesis comprises four said anchor piecesdistributed substantially regularly along an inner perimeter of saidring so that two anchor pieces are located on one side of the foldingline and the other two anchor pieces are located on the other side ofsaid folding line, all four anchor pieces are under the form ofisosceles triangles of textile, each triangle being fixed to said meshvia its base, all four triangles showing identical elongation andtensile strength properties in the centripetal direction.

For example, each isosceles triangle is fixed to the mesh via its baseby means of the ring, the thread-shaped element being attached to thevertex angle of the isosceles triangle. Because of the four isoscelestriangles of textile having the same mechanical properties in thecentripetal direction, when the surgeon pulls on the thread-shapedelements at the time he puts the prosthesis in place and fixes it to theabdominal wall, all anchor pieces react similarly and the tractionexerted by the surgeon on the whole prosthesis via the thread-shapedelements is regularly distributed. The prosthesis is therefore properlypositioned. In addition, in embodiments where the four isoscelestriangles of textile have a colour different from that of the mesh, thesurgeon readily identifies the stitching line as defined above and thestep of fixing the prosthesis to the abdominal wall is facilitated. Aswill appear from the description below, the method of manufacturing aprosthesis with four anchor pieces under the form of four isoscelestriangle of textile having identical mechanical properties is simple andeasy.

The present invention will emerge more clearly from the descriptiongiven hereinafter and from the appended drawings, in which:

FIG. 1 is a representation in section of a median abdominal hernia orventral rupture,

FIG. 2 is a simplified view of the hernia from FIG. 1 after the surgeonhas made an abdominal incision and removed the hernia sac,

FIG. 3 is a top view of one embodiment of a mesh for a prosthesis of theinvention,

FIG. 4 is a top view of a reinforcing member for the prosthesis of theinvention,

FIGS. 5A to 5D are views of anchor pieces of the prosthesis of theinvention,

FIG. 6 is a top view of a first embodiment of the prosthesis of theinvention,

FIG. 7 is a top view of another embodiment of the prosthesis of theinvention,

FIG. 8 is a top view of another embodiment of the prosthesis of theinvention,

FIG. 9 is a top view of another embodiment of the prosthesis of theinvention,

FIG. 10 is a simplified sectional view of the introduction of theprosthesis from FIG. 8 into the hernia defect,

FIG. 11 is a simplified sectional view of the positioning of theprosthesis from FIG. 8 after deployment thereof at the implantationsite,

FIG. 12 is a simplified sectional view of the fixing of the prosthesisfrom FIG. 8 to the abdominal wall,

FIG. 13 is a view in section of the prosthesis from FIG. 8 when fixed tothe biological tissues just before closure of the abdominal incision bythe surgeon,

FIG. 14-17 are top views showing the successive steps of themanufacturing process of a prosthesis of the invention comprising fouranchor pieces of textile of identical mechanical properties.

FIG. 1 represents a hernia defect 100 of the abdominal wall 101 that ischaracterized by a break in the continuity of the aponeurosis 102surrounding the straight muscles 103 and a passage through theperitoneum 104 forming a sac, the hernia sac 105, that contains eitherfat (epiploon) or part of the viscera 106, and which then presses on thefatty tissues 107 and is flush with the skin 108. One treatment of ahernia defect 100 entails replacing and retaining the viscera 106 in theabdominal cavity 109.

FIG. 2 shows the hernia defect 100 from FIG. 1 after the surgeon hasmade an incision in the skin 108, the abdominal wall 101 and theperitoneum 104 and has reduced the hernia sac. The viscera are not shownin FIG. 2: they have been pushed back into the abdominal cavity 109. Thesurgeon must now introduce into the abdominal cavity 109, via theincision 110 that has been made, a prosthesis for reinforcing theabdominal wall, before closing the incision 110 by means of sutures, forexample. In the case of an umbilical hernia, the size of the incision110 is particularly small, for example of the order of 1 to 4 cmdiameter.

FIG. 3 represents a mesh 1 in the form of a disc usable with thereinforcing member from FIG. 4 and anchor pieces such as that from FIGS.5A to 5D to produce a prosthesis of the invention.

The mesh 1 is made from a knitted, woven or non-woven arrangement ofbiocompatible threads. It may be bioresorbable, partly bioresorbable orpermanent. The mesh is generally openwork, incorporating pores forbetter tissue integration. This mesh 1 is sufficiently flexible to befolded when the prosthesis is introduced into the abdominal cavity 109via the incision 110. However, the mesh is generally a textile having noelasticity enabling it to return to a spread out configuration of itsown accord after it has been folded up. The mesh 1 may be produced froma textile layer or a plurality of textile layers. The textile may be atwo-dimensional or three-dimensional knitted fabric. Such meshes arewell known to the person skilled in the art and are not described inmore detail here. The mesh may be supplied in the form of a strip thatis cut to the dimensions of the defect to be treated. In the examplerepresented, the mesh 1 has the shape of a disc adapted to the shape ofthe incision 110 at the hernia defect 100 and delimited by an exteriorperipheral edge 1 a. In other embodiments, the mesh may be of ovalshape. Alternatively, the mesh may be of rectangular or square shape.

FIG. 4 represents a reinforcing member of a prosthesis of the invention,suitable for the shape of the mesh 1 from FIG. 3: as is apparent fromFIG. 4 and FIG. 6, the reinforcing member takes the form of a frame 2substantially adopting the shape of the exterior peripheral edge 1 a ofthe mesh 1. Thus the overall shape of the frame 2 is a circular ring.The frame 2 is provided with two hinge points 3 a and 3 b that arediametrically opposite in the example shown. The two hinge points (3 a,3 b) make it possible to fold the frame 2, for example when force isapplied by the surgeon, resulting in two globally identical parts. Thehinge points (3 a, 3 b) preferably do not have any elasticity of theirown: thus, once folded in two, the frame 2 can be unfolded only by theaction of an external force, for example exerted by the surgeon.

The frame 2 thus consists of two parts, namely two semicircles 2 a and 2b, connected together by two hinge points (3 a, 3 b). As seen in FIG. 4,the respective ends (2 c; 2 d) of the semicircles 2 a and 2 b areblunted or rounded to prevent trauma when implanting the prosthesis. Inthe example shown, the two semicircles 2 a and 2 b are symmetrical: thetwo hinge points (3 a; 3 b) define a median line M passing through thecentre of the circle delimited by the frame and also through the centreof the mesh 1 when the frame 2 is fixed to the mesh 1, as shown in FIG.6. Thus the mesh 1 may be folded in two even when fitted with the frame2: consequently, as will become apparent in the remainder of thedescription, the prosthesis may be folded. Similarly, given theconfiguration of the frame 2 in two parts and the absence of anyelasticity of the frame 2 and its hinge points (3 a, 3 b), theprosthesis is able to adopt only two configurations: either a flat andspread out configuration or a folded in two configuration. As explainedlater, the fact that the prosthesis can adopt only two configurationsfacilitates the task of the surgeon, who can immediately determine ifthe prosthesis is in its spread out configuration or not.

As seen in FIGS. 4 and 6, the frame 2 is an undulating ring set backfrom the exterior peripheral edge 1 a, consisting of undulations 4.Referring to FIG. 6 in particular, the exterior peripheral edge 1 a ofthe mesh extends some distance beyond the exterior contour of the frame2: this distance may be greater than or equal to 1 mm, for example. Aswill become apparent from the description given hereinafter, thelocation of the frame 2, slightly set back from the exterior peripheraledge 1 a, facilitates efficacious fixing of the prosthesis to theabdominal wall, in particular in an area located more or less half waybetween the centre and the edge of the mesh, this area being adjacent tothe interior contour of the frame 2.

The undulations 4 of the frame 2 may be regular or not. In particular,in the example shown, the frame 2 is in the form of a flat ribbon ofmaterial forming undulations 4 in the plane of the frame 2, which issubstantially the plane of the prosthesis. As will become apparent inthe remainder of the description, such a shape imparts to the frame 2great flexibility in the plane of the frame 2 and thus in the plane ofthe prosthesis: it is thus possible to suture part of the prosthesis ata given place, without rocking or deforming the prosthesis as a whole:the deformation created at the location of the suture is smoothed out bythe undulations 4 of the frame 2 over the whole of the periphery of theprosthesis. In addition, the frame 2 shows a rigidity along its section,so that it neither deforms radially in the outward nor in the inwarddirections.

Materials suitable for producing the reinforcing member of theprosthesis of the invention may be any biocompatible materials havingsome rigidity so as to respond to the expectations disclosed above.

The frame 2 can thus be produced in any biocompatible material,bioresorbable or not. In a preferred embodiment, it is made inbioresorbable material. In the present application, the term“bioresorbable” refers to the characteristic whereby a material isabsorbed by biological tissues and disappears in vivo after a givenperiod, which may vary from one day to several months, for example,depending on the chemical nature of the material.

Bioresorbable materials suitable for the fabrication of the reinforcingmember of the prosthesis of the present invention include polylacticacid (PLA), polycaprolactone (PCL), polydioxanone (PDO), trimethylenecarbonate (TMC), polyvinyl alcohol (PVA), polyhydroxyalkanoate (PHA),oxidized cellulose, polyglycolic acid (PGA), copolymers of thesematerials and mixtures thereof. Bioresorbable materials suitable for thefabrication of the reinforcing member of the prosthesis of the inventioninclude polyester (glycolid, dioxanone, trimethylene carbonate)available from the company Covidien under the trade name “BIOSYN®” andpolyester (glycolid, caprolactone, trimethylene carbonate, lactid)available commercially from the company Covidien under the trade name“CAPROSYN®”.

Non-bioresorbable materials suitable for the fabrication of thereinforcing member of the prosthesis of the present invention includepolypropylene, polyesters such as polyethylene terephthalate, polyamide,silicone, polyetheretherketone (PEEK), polyaryletheretherketone (PAEK)and mixtures thereof.

Each part of the reinforcing member of the prosthesis of the inventionmay be made in one piece, for example, by injection moulding one or morebiocompatible thermoplastic or thermosetting materials. The hinge points(3 a, 3 b) of the frame 2 may be produced in the same material as therest of the frame: these hinge points (3 a, 3 b) take the form forexample of very thin bridges of material in order to enable folding ofthe frame 2 without causing separation of the two parts joined togetherby these bridges.

With reference to FIGS. 5A to 5D are shown, on their own, examples ofanchor pieces 5 suitable for the prosthesis of the invention, eachprovided with a thread-shaped element (6, 7). The anchor pieces may showany geometrical shape, for example triangular, squared, semicircular.They may be identical or different for a single prosthesis.

In embodiments, such as those shown on FIGS. 5A to 5B, the anchor pieces5 show a geometrical shape where at least one side has a length greaterthan or equal to that of the other sides. Thus, with reference to FIG.5A, the anchor piece 5 has the shape of a triangle. In this example, thetriangle is isosceles and the basis B of the triangle is the side havingthe greatest length. As will appear hereinafter, the longest side of theanchor piece 5 will form the fixed part 5 a of the anchor piece 5 whilethe area located around the summit C opposed to that basis B will formthe free part 5 b of the anchor piece 5. In the same way, with referenceto FIG. 5B, the anchor piece 5 having globally the shape of a semi-disc,the diameter D forms the side of greater length of the anchor piece andwill therefore form the fixed part 5 a of the anchor piece, while therounded part forms the free part 5 b of the anchor piece 5. Withreference to FIG. 5C, the anchor piece has globally the shape of anisosceles triangle the basis of which is an arc of circle: this basiswill form the fixed part 5 a of the anchor piece, while the area locatedaround the summit opposed to that arc of circle will form the free part5 b of the anchor piece 5.

On FIG. 5D is shown an anchor piece 5 of trapezoid shape, the parallelsides of which show an arc of circle shape: the longest arc of circleforms the fixed part 5 a of the anchor piece, while the area locatedaround the shortest arc of circle forms the free part 5 b of the anchorpiece.

On FIGS. 5A to 5B, the free part 5 b of each anchor piece is linked to athread-shaped element. In the context of the present application, by“thread-shaped element”, is meant a flexible and elongated element, thelength of which is much more greater than its thickness and its width,the contour of the cross section of which is globally circular: examplesof thread-shaped elements of the invention may be a thread on its own,composite or not, or several threads, for example arranged together tomake a braid, a tube, and combinations thereof. In embodiments, thethread-shaped elements are selected from threads, tubes and combinationsthereof.

As will be apparent from the following detailed description, thethread-shaped element is intended to allow the surgeon to pull on theanchor piece linked thereto in order to expand, orientate and positionthe prosthesis when said prosthesis is put in place: preferably, thesurgeon will pull simultaneously on the thread-shaped elements of the atleast two anchor pieces which are present in order to centre andcounterbalance the prosthesis with respect to the defect to be treated.

With reference to FIG. 5A, the free part 5 b of the anchor piece islinked to a thread 6 passing through said free part 5 b. On the exampleshown, the thread 6 forms a loop. Alternatively, the thread 6 may beattached by one of its ends to the free part 5 b of the anchor piece 5.With reference to FIG. 5B, the free part 5 b of the anchor piece is alsolinked to a thread 6 passing through said free part 5 b, said thread 6forming a loop at the location of said free part 5 b, the two strands ofthe loop being further brought together within a tube 7.

With reference to FIG. 5C, the free part 5 b of the anchor piece 5 islinked to a tube 7: on the example shown, the two ends 7 a and 7 b oftube 7 are attached to the free part 5 b and the tube 7 forms a loop.With reference to FIG. 5D, the free part 5 b of the anchor piece 5 islinked to one end 7 a of a tube 7.

The tube 7 is flexible and, because of its hollow structure,necessitating a certain outer diameter, for example equal to or greaterthan 3 mm, it shows a quite important outer surface capable of being incontact with the margins of the defect, this allowing decreasingdramatically the potential traumatic effect due to the contact of thetube 7 with the margins of the defect. The flexible tube 7 may be inplastic material, silicone, or in a combination of these materials.

The anchor pieces 5 of the prosthesis of the invention are made of asuturable material: in the context of the present application, it ishereby meant that the anchor piece 5 is capable of being linked to, orpassed through by, a thread-shaped element, such as a thread 6 or a tube7, without being torn off when a user, such as a surgeon for example,exerts a moderate tension on said thread-shaped element, such as thenecessary tension for orientating and/or positioning the prosthesis inthe implantation site, as described hereinafter. The anchor pieces 5 maybe made of any biocompatible suturable material giving them thenecessary flexibility for being grasped by the surgeon when theprosthesis is put in place, as will be described hereinafter.

The anchor piece 5 may be under the form of a textile, either knitted,woven or nonwoven, open worked or not; alternatively or in addition, theanchor piece may be under the form of a film or a sheet of material, aslong as this textile, film and/or sheet of material is not torn offunder the effect of the moderate tension as described above exerted on athread-shaped element linked to, or passing through, said textile, filmand/or sheet.

As will be apparent from the following description, the anchor piecesare useful to the surgeon for facilitating the positioning of theprosthesis in the centre of the defect to be treated, and for attachingthe prosthesis to the biological tissues. The anchor pieces also formthe parts of the prosthesis by which said prosthesis is sutured to theabdominal wall.

With reference to FIG. 6 is shown a prosthesis 200 according to theinvention, comprising the mesh 1 of FIG. 3, the reinforcing member 2 ofFIG. 4 and two anchor pieces 5 similar to the anchor piece of FIG. 5C,each anchor piece 5 being on that FIG. 6 linked to a thread-shapedelement under the form of a thread 6.

As is apparent from this FIG. 6, the anchor pieces 5 are each attachedto the mesh 1 by their longer side forming the fixed part 5 a of theanchor piece: the fixing of each anchor piece 5 by its longer sideallows a more reliable fixation. Moreover, the fixed part 5 a of eachanchor piece 5 is attached along the direction of the line P which isperpendicular to the segment S linking the centre of the mesh and thepoint of fixation of each piece in the plane of the mesh. The fixed part5 a or longer side of each anchor piece is fixed to the mesh for exampleby sewing. Alternatively, it may be fixed to the mesh 1 by gluing,welding or by means of the reinforcing member 2.

The anchor pieces 5 being fixed to the mesh by their longest side, theydo not impede the surgeon at the time of the prosthesis is implanted. OnFIG. 6, the two anchor pieces 5 are fixed to two diametrically opposedplaces of an inner perimeter of the ring 2, said two places being spacedby 90° from each of said two hinge points (3 a, 3 b).

With reference to FIGS. 7 to 9 are shown prosthesis 200 of the inventionmade with the mesh 1 from FIG. 3, the frame 2 from FIG. 4 and fouranchor pieces 5 from FIG. 5A, linked to various thread-shaped elements.

In these embodiments, the four anchor pieces 5 are arranged regularlyalong an inner perimeter of the ring formed by the frame 2 so that twoanchor pieces 5 are located on one side of the folding line M and thetwo other anchor pieces are located on the other side of the foldingline M: the four anchor pieces therefore counterbalance one another.Each anchor piece 5 is fixed to the mesh 1 by its fixed part 5 a, thefree parts 5 b being left flying and forming flaps. For example, eachfixed part 5 a is attached to the mesh 1 by a seaming 8. Moreover, asingle thread-shaped element (6, 7) links together the free parts 5 b oftwo anchor pieces 5 located on the same side of the folding line M.

With reference to FIG. 7, the thread-shaped element is under the form ofa combination of a thread 6 and a tube 7: the thread 6 forms a loop atthe place of the free part 5 b of the anchor piece it is linked to, thetwo strands of the loop being brought together within a tube 7 at theplace of grasping of the thread-shaped element by the surgeon. Such anembodiment allows an easier and more comfortable grasping of thethread-shaped element by the surgeon.

With reference to FIG. 8, the thread-shaped element is under the form ofa tube 7: the first end 7 a of the tube 7 is attached to the free partof a first anchor piece 5 while the second end 7 b of the same tube 7 isattached to the free part 5 b of the adjacent anchor piece located onthe same side of the folding line M as the first anchor piece 5. Such anembodiment, in which the thread-shaped element is a tube 7, allows aneasier and more comfortable grasping of the thread-shaped element, whilelimiting the risk of trauma when the thread-shaped element contacts themargins of the defect to be treated at the time of positioning theprosthesis 200. The tube 7 may itself contain one or several threads.

With reference to FIG. 9, the thread-shaped element is under the form ofa thread 6 forming a loop at the place of the free part 5 b of a firstanchor piece 5 and at the place of the free part 5 b of a adjacentanchor piece located on the same side of the folding line M as the firstanchor piece 5.

The presence of the four anchor pieces 5, regularly distributed asdescribed above in FIGS. 7 to 10, and of the thread-shaped elementslinking anchor pieces 5 by pairs enables the surgeon to optimally spreadout the prosthesis 200 on the implantation site and to balance thetension between the various anchor pieces 5 at the time of positioningthe prosthesis 200 and to centre the latter prosthesis better relativeto the defect to be closed.

In one embodiment of the prosthesis 200 not shown, the reinforcingmember, namely the frame 2, is welded directly to the mesh 1 and to thefixed parts 5 a of anchor pieces 5. Thus the frame 2 is fastened both tothe mesh 1 and to the anchor pieces 5.

In the FIG. 8 embodiment, the face of the mesh 1 opposite that includingthe anchor pieces 5 is covered by a non-adherent coating 201. Such anon-adherent coating makes it possible to avoid in particular theformation of unwanted severe post-operative fibrous adhesions; once theprosthesis 200 has been implanted, the face of the prosthesis 200covered by the non-adherent coating 201 faces the abdominal cavity 109.

The non-adherent coating or material is chosen from bioresorbablematerials, non-bioresorbable materials and mixtures thereof. Thenon-bioresorbable non-adherent materials may be chosen frompolytetrafluoroethylene, polyethylene glycol, polysiloxane,polyurethane, and mixtures thereof.

Said non-adherent coating or material is preferably bioresorbable:bioresorbable materials suitable for said non-adherent coating may bechosen from collagen, oxidized cellulose, polyacrylate, trimethylenecarbonate, caprolactone, dioxanone, glycolic acid, lactic acid,glycolide, lactide, polysaccaride, for example chitosan, polyglucuronicacid, hyaluronic acid, dextran and mixtures thereof.

The non-adherent coating makes it possible to protect the mesh 1 of theprosthesis 200 at least during the initial scar formation phase, i.e.the mesh 1 is not exposed to inflammatory cells, such as granulocytes,monocytes, macrophages or the giant multinucleated cells generallyactivated by surgery. At least during the initial scar formation phase,the duration of which may vary from about 5 days to about 10 days, onlythe non-adherent coating is accessible to the various factors such asproteins, enzymes, cytokines or inflammatory cells.

If the non-adherent coating consists of non-resorbable materials, itthus protects the mesh 1 before and after implantation and throughoutthe duration of implantation of the prosthesis 200.

Moreover, thanks to the non-adherent coating, surrounding fragiletissues, such as the hollow viscera, for example, are protected, inparticular from unwanted severe post-operative fibrous adhesion.

If the non-adherent material includes a bioresorbable material, it ispreferable to choose a bioresorbable material that is not resorbed inless than a few days in order for the non-adherent coating to be able tofulfil its function of protecting the intestine and hollow organs duringthe days following surgery until cellular rehabilitation of theprosthesis takes over protecting these fragile organs.

Because of its two-part reinforcing member, namely the frame 2consisting of the two semicircles 2 a and 2 b in the example shown,connected together by hinge points 3 a, 3 b, the prosthesis 200 of theinvention may adopt a folded configuration after the surgeon folds italong the folding line M. Thus to implant the prosthesis 200 the surgeonfolds it in two so that it occupies a smaller volume, which facilitatesintroduction of the prosthesis into the hernia defect 100 (see FIG. 2)by the surgeon.

The mesh 1 and the non-adherent coating 201 are sufficiently flexible tofollow successive deformations of the prosthesis 200 as the latter isintroduced to the implantation site.

FIGS. 14-17 describe various steps of a method for manufacturing anembodiment of a prosthesis 210 of the invention made with the mesh 1 ofFIG. 3, the frame 2 of FIG. 4 and four anchor pieces 215. For clarity'ssake, the thread-shaped elements are not shown on FIGS. 14-17: thesethread-shaped elements may be any one of FIGS. 6-9 and may be attachedto said anchor pieces 215 as described above.

As will appear from the description below, the four anchor pieces 215 ofprosthesis 210 are arranged symmetrically along the interior contour ofthe ring formed by the frame 2, and they all have the same mechanicalproperties.

The manufacturing process of such embodiments will now be described withreference to FIGS. 14-17.

With reference to FIG. 14, is shown a textile 20 for forming the anchorpieces 215 of the prosthesis 210 (see FIG. 17). On the example shown,the textile 20 has the shape of a square, the length of one side of thesquare being greater than the greater diameter of the intended resultingprosthesis 210. This textile 20 may be identical to that forming themesh 1 or different. The textile 20 is for example produced on aknitting machine and has a warp direction Wa and a weft direction We, asshown on this FIG. 14. The textile 20 may have different mechanicalproperties, such as elongation and tensile strength, along its warpdirection Wa and along its weft direction We.

Preferably, the textile 20 has a colour different from that of the mesh1.

In order to proceed with the manufacturing of the four anchor pieces215, a cutting 21 having the shape of a cross with two perpendicularbranches (22, 23) is completed on textile 20, with one branch 22 of thecross parallel to the warp direction Wa and the other branch 23 of thecross parallel to the weft direction We, as shown on FIG. 15. Thebranches of the cross may be of identical lengths or not. On the exampleshown on FIG. 15, the length of the branch 22 parallel to the warpdirection Wa is smaller than the length of the branch 23 parallel to theweft direction. In addition, on this example and as will appear fromFIG. 16, the length of the branch 22 parallel to the warp direction Wais smaller than the diameter of the internal perimeter of the frame 2,whereas the length of the branch 23 parallel to the weft direction isgreater than the diameter of the outer perimeter of the frame 2.

In a further step, the textile 20 is laid upon a piece of mesh 1, forexample of similar square shape and dimensions as the textile 20, andthe frame 2 of FIG. 4 is then welded to both the mesh 1 and the textile20.

As shown on FIG. 16, the frame 2 is welded on mesh 1 and textile 20 sothat the greater branch 23 of the cutting 21 is applied on the foldingline M defined by the frame 2 (see FIG. 4) and extends beyond the hingepoints (3 a, 3 b) of the frame 2, whereas the smaller branch 22 of thecutting 21 does not reach the frame 2. Such an embodiment allows abetter efficiency of the frame 2, which may not be damaged by residualfilaments coming from the cutting of branch 22 when said frame 2 iswelded on both the mesh 1 and the textile 20.

Once the frame 2 is welded, the disc-shape prosthesis 210 may bemanufactured by cutting the mesh 1 and textile 20 in excess beyond theouter peripheral border of the frame 2, as shown on FIG. 17. As appearsfrom this Figure, the frame 2 forms together with the cross-shapedcutting 21 four isosceles triangles 24, more or less fixed to the frame2 by their respective base 24 a and free at their vertex angle 24 b.These four isosceles triangles 24 of textile 20 form the anchor pieces215 of the prosthesis 210.

As mentioned above, a thread-shaped element (not shown) may then beattached to the free vertex angle 24 b of each triangle 24 by anyfixation means such as those described above at FIGS. 6-9, in line withthe direction defined by the altitude 24 c drawn from the vertex angle24 b of each triangle 24.

Because of the specific cross-shaped cutting 21, with one branchparallel to the warp direction Wa and the other branch parallel to theweft direction We, all four isosceles triangles 24 of textile 20 areidentical and they all show the same mechanical properties, such aselongation properties and tensile strength properties, each in thedirection of its altitude 24 c corresponding to the centripetaldirection of the disc-shape prosthesis 210, regardless from the factthat the initial elongation and tensile strength properties of thetextile 20 in its warp direction Wa were identical or not to its initialelongation and tensile strength properties in the weft direction We.

Indeed, because of the location of the cutting 21 with respect to theframe 2 during the welding step, the altitude direction or centripetaldirection for each triangle 24 forms an angle of 45° with respect toboth warp and weft directions of the initial textile 20.

As a consequence, all four anchor pieces 215 show the same mechanicalproperties, in particular elongation properties and tensile strengthproperties, in the direction corresponding to the direction of thealtitude 24 c of each triangle 24, in other words in the directioncorresponding to the direction of the traction exerted by the surgeonwhen he pulls on the thread-shaped element (not shown) in order to putthe prosthesis in place and to fix it to the abdominal wall.

As a consequence, when the surgeon pulls on the thread-shaped element atthe time he puts the prosthesis 210 in place and fixes it to theabdominal wall, all anchor pieces 215 react similarly and the tractionexerted by the surgeon on the whole prosthesis 210 via the four anchorpieces is equally distributed. The prosthesis 210 is therefore properlypositioned. In addition, because the four isosceles triangles 24 oftextile 20 have a colour different from that of the mesh 1, the surgeonreadily identifies the stitching line as defined above. The step offixing the prosthesis 210 to the abdominal wall is thereforefacilitated.

The method of manufacturing the prosthesis 210 described above is verysimple and allows starting from a single piece of textile 20 formanufacturing the four anchor pieces 215.

Alternatively, the prosthesis 210 may be manufactured by preparinginitially four separate triangles 24 of textile 20 and welding eachtriangle 24 to the mesh 1 via the frame 2, or alternatively by preparingtwo pieces of semi-discs of textile 20, completing a perpendicularcutting on each semi-disc and welding the two cut semi-discs to the meshvia the frame 2.

Like the prosthesis 200 of FIGS. 1-13, the prosthesis 210 of FIG. 17 maybe coated on the face of the mesh 1 opposite that including the anchorpieces 215 with a non-adherent coating 201.

The fitting of a prosthesis of the invention, for example the prosthesis200 from FIG. 8, is described next with reference to FIGS. 10 to 13.Although not described, the fitting of the prosthesis 210 of FIG. 17 maybe completed in the same manner as that described hereinafter forprosthesis 200 of FIG. 8.

After making the incision 110 described with reference to FIG. 2, thesurgeon grasps the prosthesis 200 from FIG. 8, covered with anon-adherent coating 201 on the face of the mesh 1 opposite thatincluding the anchor pieces 5, and applies force to the prosthesis 200with his fingers to fold it along the folding line M. Because of thepresence of the two hinge points 3 a and 3 b, this operation is withoutdifficulty and totally independent of the elastic or non-elastic natureof the frame 2. In the embodiment shown, the prosthesis 200 being adisc, it is folded along one of its diameters, resulting in twoidentical parts. In this folded configuration, the prosthesis 200occupies a small volume and the surgeon may easily introduce it into theabdominal cavity 109, as shown in FIG. 10, while holding thethread-shaped elements, in other words the tubes 7 in the example shown,outside the body of the patient. Because of their structure, thethread-shaped elements allow limiting the volume of the various elementswhich need to be passed through the hernia defect. For clarity, thefingers of the surgeon are not represented in FIGS. 10 to 13.

Once the prosthesis 200 is in the abdominal cavity 109, the surgeonreleases the pressure on it. It is the surgeon who manually deploys theprosthesis 200 in a perfectly tensioned and spread out configuration.Thus, the prosthesis 200 being able to adopt only two positions, namelyfolded in two or spread out, the surgeon is certain that the prosthesisis perfectly spread out from the moment of unfolding the prosthesis 200.

In the next step, as shown in FIG. 11, the surgeon uses thethread-shaped elements, i.e. the tubes 7, both to centre the prosthesis200 relative to the incision 110 and to press the prosthesis 200 againstthe abdominal wall (101, 104). To this end, the surgeon pulls the tubes7 toward the exterior of the body of the patient and in oppositedirections. The surface of the tubes 7 capable of being in contact withthe margins of the defect being quite important, the risk of trauma islow. Moreover, the distribution of the anchor pieces 5 as explainedabove allows balancing and centring the prosthesis 200 on the defect tobe treated while pressing said prosthesis on the abdominal wall. Thusthe prosthesis 200 is spread perfectly and there is no risk of theviscera being disposed between the anchor pieces 5 and the abdominalwall (101, 104).

Once the prosthesis 200 is correctly positioned relative to the herniadefect, the surgeon raises a part of the edge of the hernia with thehelp of the tubes 7 and thus uncovers a central area 12 in the vicinityof the prosthesis 200, delimited overall by the anchor pieces 5, whicharea the surgeon may easily view and in which the surgeon is able towork easily.

In an embodiment, the tubes 7 are flexible and semi-rigid. Such asemi-rigidity of the tubes 7 allows maintaining the anchor pieces 5 towhich they are linked under slight tension, without having to apply anyparticular tension on these tubes: as such, once the surgeon has raisedthe edges of the hernia defect by pulling on the flexible and semi-rigidtubes 7 in order to uncover a working area, he can release the tensionon the tubes 7: the anchor pieces 5 remain under slight tension andmaintain the edges of the defect in a raised position.

In embodiments, the anchor pieces 5 are of a colour different than thatof the mesh 1: indeed, because the fixation area of the prosthesis 200to the abdominal wall (101, 104) is located more or less in the middlebetween the centre 1 b of the mesh 1 and the edge of the mesh, thesurgeon can differentiate the different colours between the variouselements forming the prosthesis 200 and thus easily identify the anchorpieces 5 he has to suture: such a thing is not possible with theprosthesis of the prior art intended to be fixed to the abdominal wallat their periphery. In particular, the colour difference between theanchor pieces 5 and the mesh 1 defines a line, said line pointing out tothe surgeon where to complete the stitches for fixing the prosthesis 200to the abdominal wall. This fixing line, or stitching line, globallycorresponds to the interior contour of the frame 2. Also, for the samereasons, the thread-shaped elements, like the tubes 7, may be of acolour different from that of the mesh and from that of the anchorpieces 5.

In a following step, as shown in FIG. 12, the surgeon proceeds to fixthe prosthesis 200 to the biological tissues by using a needle 9 and asuture 10 to suture the free part 5 b of each anchor piece 5 to theabdominal wall 101, 104 within the central working area 12. During thisstep, the whole of the prosthesis 200 remains perfectly spread out andperfectly pressed onto the abdominal wall 104, notably by virtue of thepresence of the undulations 4 of the frame 2, which smooth outdeformations caused by the surgeon in the area of the prosthesis 200that is in the process of being sutured. The surgeon may execute one ormore stitches 11 (see FIG. 13) for each free part 5 b of the four anchorpieces 5.

As may be seen in FIG. 13, the structure of the prosthesis 200 of theinvention enables the surgeon to place the stitches 11 in an areasituated more or less in the middle between the centre of the mesh 1 andthe exterior peripheral edge 1 a thereof; thus the surgeon does not haveto execute stitches at the exterior peripheral edge 1 a of the mesh 1,which can be viewed only with difficulty because of the small size ofthe incision 110. The mesh 1 nevertheless remains perfectly pressedagainst the abdominal wall 104 along this peripheral edge 1 a because ofthe presence of the frame 2. Nevertheless, because of the structure ofthe prosthesis 200 of the invention, the stitches 11 are advantageouslysituated at some distance from the defect, in particular in an area moreor less in the middle between the centre 1 b of the mesh (which is thelocation of the hernia defect) and the edge 1 a of the mesh, at alocation where the biological tissues are often healthier and lessfragile than at the margin of the defect. The stitches 11 may forexample be U-shaped, i.e. obtained with a thread provided with a needleat each of its ends.

Once the surgeon has executed the necessary stitches 11 over all theanchor pieces 5, he cuts each thread-shaped element, here each tube 7,at its junction with the free part 5 b of the anchor piece 5 in order toretain at the implantation site only the anchor pieces 5, as shown inFIG. 13. This figure shows the stitches 11 that fix the free parts 5 bof the anchor pieces 5 to the abdominal wall 104. As may be seen in FIG.13, the prosthesis 200 is thus perfectly deployed, spread out andpressed against the abdominal wall (101, 104) with no risk of trappingviscera between the prosthesis 200 and the abdominal wall (101, 104).

The surgeon then has only to close the incision 110 in the conventionalway for small size hernias, i.e. by stitches.

The prosthesis of the invention is particularly simple to install, thesurgeon being easily able to uncover a comfortable and non obstructedworking area, despite the restricted size of the implantation site. Thefitting of the prosthesis of the invention is also particularlyreliable, all risk of trapping the viscera being avoided. A prosthesisof the invention is particularly suitable for treating umbilical herniaswhere the abdominal incision made is of small size. The prosthesis ofthe invention is adapted to adopt a configuration in which it occupies aparticularly small volume facilitating its introduction into theabdominal cavity via a small incision without necessitating the use ofany dedicated ancillary device. Thanks to its particular structure, theprosthesis of the invention may be spread out and pressed onto theabdominal wall efficaciously, also without necessitating the use of adedicated tool to assist spreading it and it may be attached securely tothe abdominal wall at an area located more or less in the middle betweenthe centre of the prosthesis and its periphery: the surgeon is thereforeprevented from having to make stitches at far distance places, such asthe periphery of the prosthesis, that he cannot see. The prosthesis ofthe invention thus makes it possible to treat a hernia, in particular anumbilical hernia, efficaciously, simply and rapidly, minimizing the riskof relapse.

The invention claimed is:
 1. A process for making a prosthesiscomprising: forming a cut on a textile to produce a cut textile, the cutin a shape of a cross including first and second branches, placing thecut textile on a mesh, and welding a frame to the cut textile and themesh, the frame including two hinge points forming a folding linetherebetween, wherein one of the first and second branches is positionedon the folding line and extends beyond the two hinge points of theframe.
 2. The process of claim 1, wherein the textile has a squareshape.
 3. The process of claim 1, wherein the textile has a color whichis different from the mesh.
 4. The process of claim 1, wherein thetextile is a knit having a warp direction and a weft direction.
 5. Theprocess of claim 1, wherein the mesh is a knit.
 6. The process of claim4, wherein the first branch is parallel to the weft direction and thesecond branch is parallel to the warp direction of the textile.
 7. Theprocess of claim 1, wherein the first and second branches are generallyperpendicular to each other.
 8. The process of claim 1, wherein a lengthof the second branch is smaller than a length of the first branch. 9.The process of claim 1, wherein a length of the second branch is smallerthan a diameter of an inner diameter of the frame.
 10. The process ofclaim 1, wherein a length of the first branch is larger than a diameterof an outer perimeter of the frame.
 11. The process of claim 1, whereinthe frame is generally circular.
 12. The process of claim 1, wherein theframe is of serpentine shape forming undulations.
 13. The process ofclaim 1, wherein said frame takes the form of a flat ribbon formingundulations substantially in a plane of the mesh.
 14. The process ofclaim 1, further comprising cutting the cut textile and the mesh inexcess beyond an outer peripheral border of the frame to produce theprosthesis.
 15. The process of claim 1, wherein the two hinge points ofthe frame are diametrically opposed on the prosthesis.
 16. The processof claim 1, wherein the two hinge points are on the frame and thefolding line extends across a center of the prosthesis therebetween. 17.The process of claim 1, wherein the one of the first and second branchesextends beyond the frame towards an outer edge of the prosthesis. 18.The process of claim 1, wherein the frame in combination with the firstand second branches form four anchor pieces of the textile, wherein eachanchor piece includes a fixed part linked to the mesh and a free part.19. The process of claim 18, wherein the four anchor pieces areisosceles triangles.
 20. The process of claim 18, further comprisinglinking at least one thread-shaped element to the free parts of at leasttwo anchor pieces.
 21. The process of claim 20, wherein the at least twoanchor pieces are located on the same side of the folding line.
 22. Theprocess of claim 20, wherein the thread-shaped element is selected fromthreads, flexible tubes and combinations thereof.
 23. The process ofclaim 18, further comprising applying a non-adherent coating to a faceof the mesh opposite that including said anchor pieces.
 24. A processfor making a disc-shaped prosthesis comprising: forming a cut on asquare textile to produce a cut square textile, the cut in a shape of across including first and second branches, placing the cut squaretextile on a mesh, and welding a circular frame to the cut squaretextile and the mesh, the circular frame including two hinge pointsforming a folding line therebetween, wherein one of the first and secondbranches is positioned on the folding line and extends beyond the twohinge points of the frame, and cutting the cut square textile and themesh in excess beyond an outer peripheral border of the circular frameto produce a disc-shaped prosthesis.